Sunday, May 28

"A conflict in North Korea would be probably the worst kind of fighting in most people's lifetimes,” he told CBS News.

Mr Mattis said that North Korea is a “direct threat to the United States” and poses a huge risk to neighbouring countries such as Japan, China and Russia.

"But the bottom line is it would be a catastrophic war if this turns into a combat if we're not able to resolve this situation through diplomatic means," he added.

Speaking about Kim Jong-un’s rogue weapons programme, he said that the the Trump administration is assuming that “with a testing program they get better with each test”.

"They have been very clear in their rhetoric we don't have to wait until they have an intercontinental ballistic missile with a nuclear weapon on it to say that now it's manifested completely," he added.

KCNA said that the exercise tested "a new type of anti-aircraft guided weapon”.

It claimed that defects formerly present in the system have now been corrected, however experts have cast doubt on the rogue nation’s claims.

“North Korea tested the new-type anti-aircraft guided weapons system and suggested that they can even hit the stealth aircraft and ballistic missiles, but I think this is exaggeration given their level of technology at this point," Yang Uk, a North Korean expert at advisory committee for the South Korean Joint Chiefs of Staff, told NBC News.

7.00am: Fears that North Korea could be developing a new missile system have been raised, after the secretive state’s official media agency released new images of Kim Jong-un observing a test launch.

“Testing against an ICBM-type threat is the next step in that process.”

Yesterday, the G7 agreed to increase pressure and sanctions on North Korea.

Speaking at the summit in Sicily, Japanese Prime Minister Shinzo Abe said that "the threat has entered a new stage" and noted that today represents the first time that the G7 has recognised North Korea as a priority issue.

He added: “There is a danger that can spread like a contagious disease.”

It has also been reported that a third US Navy aircraft carrier will be deployed to the Western Pacific Ocean.

The USS Nimitz will join the USS Ronald Reagan and the USS Carl Vinson, which are currently stationed near to the Korean Peninsula.